Development of an online calculator for the prediction of seizure freedom following pediatric hemispherectomy using the Hemispherectomy Outcome Prediction Scale (HOPS).

OBJECTIVES: Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy. METHODS: Retrospective data of all pediatric patients with DRE and seizure outcome data from the original Hemispherectomy Outcome Prediction Scale (HOPS) study were included. The primary outcome of interest was time-to-seizure recurrence. A multivariate Cox proportional-hazards regression model was developed to predict the likelihood of post-hemispheric surgery seizure freedom at three time points (1-, 2- and 5- years) based on a combination of variables identified by clinical judgment and inferential statistics predictive of the primary outcome. The final model from this study was encoded in a publicly accessible online calculator on the International Network for Epilepsy Surgery and Treatment (iNEST) website (https://hops-calculator.com/). RESULTS: The selected variables for inclusion in the final model included the five original HOPS variables (age at seizure onset, etiologic substrate, seizure semiology, prior non-hemispheric resective surgery, and contralateral fluorodeoxyglucose-positron emission tomography [FDG-PET] hypometabolism) and three additional variables (age at surgery, history of infantile spasms, and magnetic resonance imaging [MRI] lesion). Predictors of shorter time-to-seizure recurrence included younger age at seizure onset, prior resective surgery, generalized seizure semiology, FDG-PET hypometabolism contralateral to the side of surgery, contralateral MRI lesion, non-lesional MRI, non-stroke etiologies, and a history of infantile spasms. The area under the curve (AUC) of the final model was 73.0%. SIGNIFICANCE: Online calculators are useful, cost-free tools that can assist physicians in risk estimation and inform joint decision-making processes with patients and families, potentially leading to greater satisfaction. Although the HOPS data was validated in the original analysis, the authors encourage external validation of this new calculator.

Added value of corpus callosotomy following vagus nerve stimulation in children with Lennox-Gastaut syndrome: A multicenter, multinational study.

OBJECTIVE: Lennox-Gastaut syndrome (LGS) is a severe form of epileptic encephalopathy, presenting during the first years of life, and is very resistant to treatment. Once medical therapy has failed, palliative surgeries such as vagus nerve stimulation (VNS) or corpus callosotomy (CC) are considered. Although CC is more effective than VNS as the primary neurosurgical treatment for LGS-associated drop attacks, there are limited data regarding the added value of CC following VNS. This study aimed to assess the effectiveness of CC preceded by VNS. METHODS: This multinational, multicenter retrospective study focuses on LGS children who underwent CC before the age of 18 years, following prior VNS, which failed to achieve satisfactory seizure control. Collected data included epilepsy characteristics, surgical details, epilepsy outcomes, and complications. The primary outcome of this study was a 50% reduction in drop attacks. RESULTS: A total of 127 cases were reviewed (80 males). The median age at epilepsy onset was 6 months (interquartile range [IQR] = 3.12-22.75). The median age at VNS surgery was 7 years (IQR = 4-10), and CC was performed at a median age of 11 years (IQR = 8.76-15). The dominant seizure type was drop attacks (tonic or atonic) in 102 patients. Eighty-six patients underwent a single-stage complete CC, and 41 an anterior callosotomy. Ten patients who did not initially have a complete CC underwent a second surgery for completion of CC due to seizure persistence. Overall, there was at least a 50% reduction in drop attacks and other seizures in 83% and 60%, respectively. Permanent morbidity occurred in 1.5%, with no mortality. SIGNIFICANCE: CC is vital in seizure control in children with LGS in whom VNS has failed. Surgical risks are low. A complete CC has a tendency toward better effectiveness than anterior CC for some seizure types.

Hemispherectomy Outcome Prediction Scale: Development and validation of a seizure freedom prediction tool.

OBJECTIVE: To develop and validate a model to predict seizure freedom in children undergoing cerebral hemispheric surgery for the treatment of drug-resistant epilepsy. METHODS: We analyzed 1267 hemispheric surgeries performed in pediatric participants across 32 centers and 12 countries to identify predictors of seizure freedom at 3 months after surgery. A multivariate logistic regression model was developed based on 70% of the dataset (training set) and validated on 30% of the dataset (validation set). Missing data were handled using multiple imputation techniques. RESULTS: Overall, 817 of 1237 (66%) hemispheric surgeries led to seizure freedom (median follow-up = 24 months), and 1050 of 1237 (85%) were seizure-free at 12 months after surgery. A simple regression model containing age at seizure onset, presence of generalized seizure semiology, presence of contralateral 18-fluoro-2-deoxyglucose-positron emission tomography hypometabolism, etiologic substrate, and previous nonhemispheric resective surgery is predictive of seizure freedom (area under the curve = .72). A Hemispheric Surgery Outcome Prediction Scale (HOPS) score was devised that can be used to predict seizure freedom. SIGNIFICANCE: Children most likely to benefit from hemispheric surgery can be selected and counseled through the implementation of a scale derived from a multiple regression model. Importantly, children who are unlikely to experience seizure control can be spared from the complications and deficits associated with this surgery. The HOPS score is likely to help physicians in clinical decision-making.

Epilepsy surgery in infants up to 3 months of age: Safety, feasibility, and outcomes: A multicenter, multinational study.

OBJECTIVE: Drug-resistant epilepsy (DRE) during the first few months of life is challenging and necessitates aggressive treatment, including surgery. Because the most common causes of DRE in infancy are related to extensive developmental anomalies, surgery often entails extensive tissue resections or disconnection. The literature on "ultra-early" epilepsy surgery is sparse, with limited data concerning efficacy controlling the seizures, and safety. The current study's goal is to review the safety and efficacy of ultra-early epilepsy surgery performed before the age of 3 months. METHODS: To achieve a large sample size and external validity, a multinational, multicenter retrospective study was performed, focusing on epilepsy surgery for infants younger than 3 months of age. Collected data included epilepsy characteristics, surgical details, epilepsy outcome, and complications. RESULTS: Sixty-four patients underwent 69 surgeries before the age of 3 months. The most common pathologies were cortical dysplasia (28), hemimegalencephaly (17), and tubers (5). The most common procedures were hemispheric surgeries (48 procedures). Two cases were intentionally staged, and one was unexpectedly aborted. Nearly all patients received blood products. There were no perioperative deaths and no major unexpected permanent morbidities. Twenty-five percent of patients undergoing hemispheric surgeries developed hydrocephalus. Excellent epilepsy outcome (International League Against Epilepsy [ILAE] grade I) was achieved in 66% of cases over a median follow-up of 41 months (19-104 interquartile range [IQR]). The number of antiseizure medications was significantly reduced (median 2 drugs, 1-3 IQR, p < .0001). Outcome was not significantly associated with the type of surgery (hemispheric or more limited resections). SIGNIFICANCE: Epilepsy surgery during the first few months of life is associated with excellent seizure control, and when performed by highly experienced teams, is not associated with more permanent morbidity than surgery in older infants. Thus surgical treatment should not be postponed to treat DRE in very young infants based on their age.

Comparison of the real-world effectiveness of vertical versus lateral functional hemispherotomy techniques for pediatric drug-resistant epilepsy: A post hoc analysis of the HOPS study.

OBJECTIVE: This study was undertaken to determine whether the vertical parasagittal approach or the lateral peri-insular/peri-Sylvian approach to hemispheric surgery is the superior technique in achieving long-term seizure freedom. METHODS: We conducted a post hoc subgroup analysis of the HOPS (Hemispheric Surgery Outcome Prediction Scale) study, an international, multicenter, retrospective cohort study that identified predictors of seizure freedom through logistic regression modeling. Only patients undergoing vertical parasagittal, lateral peri-insular/peri-Sylvian, or lateral trans-Sylvian hemispherotomy were included in this post hoc analysis. Differences in seizure freedom rates were assessed using a time-to-event method and calculated using the Kaplan-Meier survival method. RESULTS: Data for 672 participants across 23 centers were collected on the specific hemispherotomy approach. Of these, 72 (10.7%) underwent vertical parasagittal hemispherotomy and 600 (89.3%) underwent lateral peri-insular/peri-Sylvian or trans-Sylvian hemispherotomy. Seizure freedom was obtained in 62.4% (95% confidence interval [CI] = 53.5%-70.2%) of the entire cohort at 10-year follow-up. Seizure freedom was 88.8% (95% CI = 78.9%-94.3%) at 1-year follow-up and persisted at 85.5% (95% CI = 74.7%-92.0%) across 5- and 10-year follow-up in the vertical subgroup. In contrast, seizure freedom decreased from 89.2% (95% CI = 86.3%-91.5%) at 1-year to 72.1% (95% CI = 66.9%-76.7%) at 5-year to 57.2% (95% CI = 46.6%-66.4%) at 10-year follow-up for the lateral subgroup. Log-rank test found that vertical hemispherotomy was associated with durable seizure-free progression compared to the lateral approach (p = .01). Patients undergoing the lateral hemispherotomy technique had a shorter time-to-seizure recurrence (hazard ratio = 2.56, 95% CI = 1.08-6.04, p = .03) and increased seizure recurrence odds (odds ratio = 3.67, 95% CI = 1.05-12.86, p = .04) compared to those undergoing the vertical hemispherotomy technique. SIGNIFICANCE: This pilot study demonstrated more durable seizure freedom of the vertical technique compared to lateral hemispherotomy techniques. Further studies, such as prospective expertise-based observational studies or a randomized clinical trial, are required to determine whether a vertical approach to hemispheric surgery provides superior long-term seizure outcomes.

Comparison of anticoagulation and antiplatelet therapy for treatment of blunt cerebrovascular injury in children <10 years of age: a multicenter retrospective cohort study.

PURPOSE: Blunt cerebrovascular injury (BCVI) is uncommon in the pediatric population. Among the management options is medical management consisting of antithrombotic therapy with either antiplatelets or anticoagulation. There is no consensus on whether administration of antiplatelets or anticoagulation is more appropriate for BCVI in children < 10 years of age. Our goal was to compare radiographic and clinical outcomes based on medical treatment modality for BCVI in children < 10 years. METHODS: Clinical and radiographic data were collected retrospectively for children screened for BCVI with computed tomography angiography at 5 academic pediatric trauma centers. RESULTS: Among 651 patients evaluated with computed tomography angiography to screen for BCVI, 17 patients aged less than 10 years were diagnosed with BCVI (7 grade I, 5 grade II, 1 grade III, 4 grade IV) and received anticoagulation or antiplatelet therapy for 18 total injuries: 11 intracranial carotid artery, 4 extracranial carotid artery, and 3 extracranial vertebral artery injuries. Eleven patients were treated with antiplatelets (10 aspirin, 1 clopidogrel) and 6 with anticoagulation (4 unfractionated heparin, 2 low-molecular-weight heparin, 1 transitioned from the former to the latter). There were no complications secondary to treatment. One patient who received anticoagulation died as a result of the traumatic injuries. In aggregate, children treated with antiplatelet therapy demonstrated healing on 52% of follow-up imaging studies versus 25% in the anticoagulation cohort. CONCLUSION: There were no observed differences in the rate of hemorrhagic complications between anticoagulation and antiplatelet therapy for BCVI in children < 10 years, with a nonsignificantly better rate of healing on follow-up imaging in children who underwent antiplatelet therapy; however, the study cohort was small despite including patients from 5 hospitals.

Stereotactic laser interstitial thermal therapy for brainstem cavernous malformations: two preliminary cases.

Brainstem cavernous malformations (CMs) often have high hemorrhage rates and significant posthemorrhage morbidity. The authors present two cases in which magnetic resonance thermography-guided laser interstitial therapy was used for treatment of pontine CMs after recurrent hemorrhage. Both patients showed significant symptomatic improvement and were hemorrhage-free at 12- and 6-month follow-up, respectively. Each had radiographic evidence of lesion involution on serial follow-up imaging. These early results demonstrate this treatment modality may be technically safe; however, larger case numbers and longer follow-up are needed to demonstrate efficacy.

Evaluation of pediatric glioma outcomes using intraoperative MRI: a multicenter cohort study.

BACKGROUND: The use of intraoperative MRI (iMRI) during treatment of gliomas may increase extent of resection (EOR), decrease need for early reoperation, and increase progression-free and overall survival, but has not been fully validated, particularly in the pediatric population. OBJECTIVE: To assess the accuracy of iMRI to identify residual tumor in pediatric patients with glioma and determine the effect of iMRI on decisions for resection, complication rates, and other outcomes. METHODS: We retrospectively analyzed a multicenter database of pediatric patients (age ≤ 18 years) who underwent resection of pathologically confirmed gliomas. RESULTS: We identified 314 patients (mean age 9.7 ± 4.6 years) with mean follow-up of 48.3 ± 33.6 months (range 0.03-182.07 months) who underwent surgery with iMRI. There were 201 (64.0%) WHO grade I tumors, 57 (18.2%) grade II, 24 (7.6%) grade III, 9 (2.9%) grade IV, and 23 (7.3%) not classified. Among 280 patients who underwent resection using iMRI, 131 (46.8%) had some residual tumor and underwent additional resection after the first iMRI. Of the 33 tissue specimens sent for pathological analysis after iMRI, 29 (87.9%) showed positive tumor pathology. Gross total resection was identified in 156 patients (55.7%), but this was limited by 69 (24.6%) patients with unknown EOR. CONCLUSIONS: Analysis of the largest multicenter database of pediatric gliomas resected using iMRI demonstrated additional tumor resection in a substantial portion of cases. However, determining the impact of iMRI on EOR and outcomes remains challenging because iMRI use varies among providers nationally. Continued refinement of iMRI techniques for use in pediatric patients with glioma may improve outcomes.

A comparison of the accuracy of fetal MRI and prenatal ultrasonography at predicting lesion level and perinatal motor outcome in patients with myelomeningocele.

OBJECTIVE: Prenatal imaging has several critical roles in the diagnosis and management of myelomeningocele, including specific family counseling and the selection of fetal surgery or postnatal repair. In this study, the authors compared the accuracy of fetal MRI and prenatal ultrasonography (US) in predicting the spinal lesion level and assessed the correlation between imaging findings and motor function as independently evaluated by a physical therapist (PT) after birth. METHODS: A retrospective review of demographic and clinical data was performed to identify children who had been treated with postnatal myelomeningocele closure at a single institution between March 2013 and December 2018. Patients were eligible for inclusion if they had all of the following: prenatal US identifying the neural tube defect level, fetal MRI identifying the neural tube defect level, and postoperative PT evaluation identifying the motor deficit level. Statistical analysis was performed using Cohen's kappa coefficient to compare the US- and MRI-demonstrated lesion level and correlate these findings with the motor level assigned postnatally by a PT via manual muscle testing. RESULTS: Thirty-four patients met the inclusion criteria. The mean gestational age at US was 23.0 ± 4.7 weeks, whereas the mean gestational age at MRI was 24.0 ± 4.1 weeks. The mean time from surgery to the PT evaluation was 2.9 ± 1.9 days. Prenatal US and MRI were in agreement within one spinal level in 74% of cases (25/34, k = 0.43). When comparing the US-demonstrated spinal level with the PT-assigned motor level, the two were in agreement within one level in 65% of cases (22/34, k = 0.40). When comparing MRI-demonstrated spinal level with the PT motor level, the two were in agreement within one level in 59% of cases (20/34, k = 0.37). MRI and US were within two spinal levels of the PT evaluation in 79.4% and 85.3% of cases, respectively. MRI and US agreed within two levels in 97.1% of cases. Prenatal US and MRI were equivalent when comparing the difference between the imaged level and the postnatal motor deficit level (mean level difference: 1.12 ± 1.16 vs 1.17 ± 1.11, p = 0.86). CONCLUSIONS: Prenatal US and MRI equivalently predicted the postnatal motor deficit level in children with myelomeningocele. These data may be valuable in prenatal prognostication.

Anterior two-thirds corpus callosotomy via stereotactic laser ablation.

Anterior two-thirds corpus callosotomy is a common palliative surgical intervention most commonly employed in patients with atonic or drop seizures. Recently, stereotactic laser ablation of the corpus callosum without a craniotomy has shown promise in achieving similar outcomes with fewer side effects and shorter hospitalizations. The authors demonstrate ablation of the anterior two-thirds corpus callosum in a patient with Lennox-Gastaut syndrome and drug-resistant drop seizures. Technical nuances of laser ablation with 3 laser fibers are described. Postoperatively, the patient showed a significant reduction in seizure frequency and severity over a 9-month follow-up period. The video can be found here: https://youtu.be/3-mMq5-PLiM .

The transcriptional network for mesenchymal transformation of brain tumours.

The inference of transcriptional networks that regulate transitions into physiological or pathological cellular states remains a central challenge in systems biology. A mesenchymal phenotype is the hallmark of tumour aggressiveness in human malignant glioma, but the regulatory programs responsible for implementing the associated molecular signature are largely unknown. Here we show that reverse-engineering and an unbiased interrogation of a glioma-specific regulatory network reveal the transcriptional module that activates expression of mesenchymal genes in malignant glioma. Two transcription factors (C/EBPbeta and STAT3) emerge as synergistic initiators and master regulators of mesenchymal transformation. Ectopic co-expression of C/EBPbeta and STAT3 reprograms neural stem cells along the aberrant mesenchymal lineage, whereas elimination of the two factors in glioma cells leads to collapse of the mesenchymal signature and reduces tumour aggressiveness. In human glioma, expression of C/EBPbeta and STAT3 correlates with mesenchymal differentiation and predicts poor clinical outcome. These results show that the activation of a small regulatory module is necessary and sufficient to initiate and maintain an aberrant phenotypic state in cancer cells.

Long-term life expectancy for children with ependymoma and medulloblastoma.

OBJECTIVES: There is a paucity of long-term follow-up data for children with intracranial ependymoma (IE) and medulloblastoma (MB). What happens to these children 20, 30, or 40 years after diagnosis? Do they have potential for a normal lifespan? The purpose of this study was to ascertain the long-term survival potential in children with MB or IE who have survived 5 years from diagnosis. METHODS: A retrospective analysis was conducted using the SEER Program. Children (ages 0-19 years) from 1973 to 2011 with a diagnosis of MB or IE were identified. A cohort was created of potentially cured patients who survived 5 years from diagnosis. Cox proportional hazards models and Kaplan-Meier estimates were utilized to analyze long-term survival. RESULTS: We identified 876 patients with MB and 474 patients with IE who were alive 5 years from diagnosis. Patients with MB had a 30-year overall survival (OS) and cancer-specific survival (CSS) of 70.2% and 80.1%, respectively. Patients with IE had a 30-year OS and CSS of 57.3% and 68.8%, respectively. When comparing MB with IE, MB had improved CSS (P = 0.04) and trended toward increased OS (P = 0.10). CONCLUSIONS: A significant number of deaths due to disease occur for several decades after treatment for both IE and MB. Despite this, the potential for long-term survival exists in 5-year survivors of both histologies. If alive at 5 years from diagnosis, patients with MB tend to have a lower risk of death from disease compared to those with IE.

Rasmussen encephalitis with dual pathology in a patient without seizures: case report and literature review.

PURPOSE: Rasmussen encephalitis without seizures is rare. We report a case of Rasmussen encephalitis and cortical dysplasia without epilepsy as well as describe the imaging, pathology, and clinical course and review the literature to investigate whether this may represent a rare subset of Rasmussen encephalitis. CASE REPORT: We report the case of a 12-year-old girl with a history of cognitive decline and right arm weakness. Magnetic resonance imaging demonstrated diffuse left hemispheric cortical and subcortical atrophy suggestive of Rasmussen encephalitis. The patient had no clinical history of seizures, and electroencephalography did not demonstrate epileptiform abnormalities. Craniotomy for open brain biopsy was performed, and histopathologic evaluation identified Rasmussen encephalitis with cortical dysplasia (dual pathology). CONCLUSIONS: To the best of our knowledge, this is the third case of Rasmussen encephalitis diagnosed by both imaging and histopathology that had no clinical or electroencephalographic evidence of seizures and is the only case of Rasmussen encephalitis with cortical dysplasia without epilepsy.

Primary T cell central nervous system lymphoblastic lymphoma in a child: case report and literature review.

PURPOSE: Primary central nervous system lymphoma (PCNSL) of T cell origin is rare in pediatric patients. We report a case of T cell PCNSL in a 12-year-old boy and review the literature to highlight the importance of brain biopsy to definitively establish the diagnosis when PCNSL is suspected. CASE REPORT: A 12-year-old boy presented with worsening left-sided weakness, nausea, vomiting, headache, blurred vision, and diplopia. Magnetic resonance imaging revealed right parietal gyral thickening with faint meningeal contrast enhancement. No clear diagnosis was identified after serum testing, cerebrospinal fluid analysis, and cerebral angiography. To establish the diagnosis definitively, a right craniotomy and open, frameless stereotactic biopsy were performed, which yielded the diagnosis of lymphoblastic T cell lymphoma. CONCLUSIONS: PCNSL of T cell origin in children remains poorly studied, with only 18 detailed cases reported over the last three decades, including this case. Establishing a definitive diagnosis of PCNSL is challenging, and a brain biopsy is often required to obtain enough tissue for pathological analysis. Increasing awareness and identification of children diagnosed with T cell PCNSL is needed to better understand the molecular biology of this disease and develop more standardized treatment regimens.

Management of External Ventricular Drains for Neuromonitoring and Traumatic Brain Injury Treatment in Pediatric Patients Outside of Intensive Care Units: A Single-Institution Retrospective Study.

BACKGROUND: Most pediatric hospitals manage patients who require external ventricular drains (EVDs) exclusively within pediatric intensive care units (PICUs) because of institutional protocols. Our institution commonly manages patients with EVDs on the neurotrauma floor (NTF). We evaluated whether this practice results in more EVD-associated complications. METHODS: A retrospective cohort study at our Level 1 pediatric trauma center identified all trauma patients ≤18 years old who received an EVD in 2018-2023. Demographics, presenting characteristics, in-hospital management, and EVD management details were recorded. The primary outcome was EVD-related complication events. RESULTS: Of the 81 patients who had EVDs placed after neurotrauma, 45 had their EVD managed exclusively in the PICU (PICU-EVD) and 36 had their EVD for some time while on the NTF (NTF-EVD). The groups were similar in sex (p = 0.87) and age (p = 0.054). PICU-EVD patients underwent fewer neurosurgeries (55.6% vs. 77.8%, p = 0.04) but spent more time on ventilators (10.6 ± 8.7 days vs. 6.4 ± 4.8, p = 0.02) and in the PICU (11.8 ± 9.0 days vs. 8.4 ± 5.9, p = 0.02). Total hospital stay was similar between groups (p = 0.44). NTF-EVD patients were on the drain longer (9.0 ± 7.4 days vs. 13.1 ± 9.1, p = 0.03), including 5.9 days on the NTF. Four EVD-related complications occurred overall: 2 accidental dislodgements and 2 cerebrospinal fluid leaks. EVD complication rates were similar on the NTF and PICU (2.2% vs. 8.3%, p = 0.21). All complications occurred late in the hospital course and were minor. A Poisson regression model comparing complication rates between PICU-only and NTF management (433 vs. 441 catheter days, respectively) found a complication rate of 6.8 per 1000 catheter days in the NTF group versus 2.3 per 1000 catheter days in the PICU-only group, yielding a rate ratio of 2.95 (95% confidence interval 0.29-30.4, p = 0.35). However, this difference was not statistically significant. CONCLUSION: Our center routinely discharges patients from the PICU to the NTF with EVDs in place. This practice may be associated with no increased risk or rate of EVD-related complications compared to PICU-only management. LEVEL OF EVIDENCE: IV.

Responsive Neurostimulation in Pediatric and Young Adult Patients With Drug-Resistant Focal, Multifocal, and Generalized Epilepsy: A Single-Center Experience.

BACKGROUND: Responsive neurostimulation (RNS) is used off-label in pediatric patients with drug-resistant epilepsy (DRE). Our study aims to assess the safety and efficacy of RNS in pediatric and young adult patients with focal, multifocal, and generalized DRE. METHODS: All patients who underwent RNS implantation at Primary Children's Hospital in Salt Lake City, UT, between December 2017 and 2022. RESULTS: A total of 47 patients were retrospectively identified, of which 32 patients were included in the final analysis. Patients ranged in age from five to 21 years (pediatric n = 22, young adult n = 10) at the time of RNS implantation with focal (20 [63%]), multifocal (8 [25%]), and generalized (4 [12%]) DRE. Operative complications (3 [9%]) and negative side effects (6 [19%]) were minor. At the time of most recent clinic visit (mean 18.6 months, S.D. 13.9), 19 of 32 patients (59%) were responders with ≥50% reduction in seizure frequency (pediatric n = 14, young adult n = 5). The rate of responders increased with prolonged activation of RNS stimulation, reaching 71% (five of seven patients) after 24 months. Antiseizure medication was reduced in five (16%) patients, and seizure rescue medication usage was reduced in 10 (31%) patients. Quality of life improved in 15 (47%) patients. CONCLUSIONS: RNS implantation resulted in a sustained reduction in seizure frequency with minimal side effects in a majority of patients. Taken together, our data suggest that RNS is an effective and safe treatment option for focal, multifocal, and potentially generalized DRE in the pediatric and young adult population.

Morphological and ultrastructural investigation of the posterior atlanto-occipital membrane: Comparing children with Chiari malformation type I and controls.

INTRODUCTION: The fibrous posterior atlanto-occipital membrane (PAOM) at the craniocervical junction is typically removed during decompression surgery for Chiari malformation type I (CM-I); however, its importance and ultrastructural architecture have not been investigated in children. We hypothesized that there are structural differences in the PAOM of patients with CM-I and those without. METHODS: In this prospective study, blinded pathological analysis was performed on PAOM specimens from children who had surgery for CM-I and children who had surgery for posterior fossa tumors (controls). Clinical and radiographic data were collected. Statistical analysis included comparisons between the CM-I and control cohorts and correlations with imaging measures. RESULTS: A total of 35 children (mean age at surgery 10.7 years; 94.3% white) with viable specimens for evaluation were enrolled: 24 with CM-I and 11 controls. There were no statistical demographic differences between the two cohorts. Four children had a family history of CM-I and five had a syndromic condition. The cohorts had similar measurements of tonsillar descent, syringomyelia, basion to C2, and condylar-to-C2 vertical axis (all p>0.05). The clival-axial angle was lower in patients with CM-I (138.1 vs. 149.3 degrees, p = 0.016). Morphologically, the PAOM demonstrated statistically higher proportions of disorganized architecture in patients with CM-I (75.0% vs. 36.4%, p = 0.012). There were no differences in PAOM fat, elastin, or collagen percentages overall and no differences in imaging or ultrastructural findings between male and female patients. Posterior fossa volume was lower in children with CM-I (163,234 mm3 vs. 218,305 mm3, p<0.001), a difference that persisted after normalizing for patient height (129.9 vs. 160.9, p = 0.028). CONCLUSIONS: In patients with CM-I, the PAOM demonstrates disorganized architecture compared with that of control patients. This likely represents an anatomic adaptation in the presence of CM-I rather than a pathologic contribution.

Glioblastoma of the cerebellum in children: report of five cases and review of the literature.

PURPOSE: Cerebellar glioblastomas in children are rare. As a result, an optimal treatment strategy has not yet been identified. A review of the characteristics of the disease as well as the effectiveness of various therapeutic modalities would help in optimizing the treatment paradigm. METHODS: We performed a detailed clinical, radiographic, and pathologic retrospective review of five patients (three boys and two girls, average age at presentation 7.2 years (range, 3-14 years)) and surveyed the literature for an additional 55 cases. RESULTS: Computed tomography and magnetic resonance imaging usually revealed a large lesion with minimal edema, heterogeneous contrast enhancement, and a discrete border. Subtotal tumor resection was performed in two patients and gross total resection in three patients. Immunostaining of the tumor cells with antisera to glial fibrillary acidic protein and vimentin was variably positive. Adjuvant therapy included local radiation and chemotherapy in all followed patients. Tumor recurrence was seen in two patients. Patients were followed from 2 months to 3.5 years (mean, 12 months). Two patients were dead at last follow-up with a mean survival of 9.5 months. CONCLUSIONS: The prognosis for pediatric patients with cerebellar glioblastomas is dismal, even when compared to adult counterparts or other malignant posterior fossa tumors in children. Cerebellar glioblastomas have a tendency to recur and disseminate despite treatment with surgery, chemotherapy, and radiation. The poor outcomes seen with this tumor suggest that the optimal treatment strategy has yet to be elucidated and much work needs to be done.

Management of ruptured dissecting intracranial aneurysms in infants: report of four cases and review of the literature.

BACKGROUND: Intracranial cerebral aneurysms in the pediatric population are infrequent, and those occurring in infants less than 1 year old are extremely rare. Of intracranial aneurysms in children, dissecting aneurysms are the most common type seen. While spontaneous dissecting aneurysms usually present with ischemia, hemorrhage can also occur. METHODS: A retrospective review of our patients revealed that from July 1, 2007 to June 30, 2012, four infants were treated for ruptured distal dissecting intracranial aneurysms at Texas Children's Hospital. Mycotic aneurysms and collagen vascular disorder were excluded in all four cases. All patients presented in our series presented with subarachnoid hemorrhage, and three had intraventricular hemorrhage. All patients underwent conventional catheter angiography for diagnosis. All patients in this series were managed in the acute or subacute period with surgical or endovascular trapping without distal bypass procedures. All four patients tolerated sacrifice of the parent vessels feeding these distal aneurysms well. CASE REPORT AND REVIEW OF LITERATURE: We describe the presentation and management of these rare cases and then review the current literature on the management of these dissecting aneurysms in infants.